Insulation of railroad-tracks used for electric circuits



(No Model.) T. A. EDISON.

INSULATION OF-RAILROAD TRACKS USED PORELEG RIG 0130mm. No. 2.93.433. Patented Feb. 12,1884.

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- ATTORNEYS,

- UNITED STATES PATENT @rricn.

THOMAS A. EDISON, OF MENLO PARK, EWV JERSEY, ASSIGNOR, lBY MESNE ASSIGNMENTS, TO THE ELEOTRI O RAILWAY COMPANY OF THE UNITED STATES, OF NEW YORK.

INSULATION F RAILROAD-TRACKS USED FOR ELECTRIC CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 293,433, dated February 12, 1884.

Application filed August 9, 1880. No model.)

To all whom it may concern..- tion adhering to the surface-for example, a 50 Be it known that I, THOMAS A. EDISON, of rubber paint, or a paint of which the base is Menlo Park, in the county of Middlesex and pure linseed-oil, the ties, for a space of, say, State of New Jersey, have invented a new and one-half foot to afoot on each side of the rails, useful Improvement in Insulation of Railroadbeing similarly painted.

Tracks Used as Electric Circuits, (Case No. In the drawings, Figure lis across-section, 55 238;) and I do hereby declare that the followand Fig. 4c a perspective, of a rail arranged as ing is afull and exact description of the same, described. Figs. 2 and 3 are views of details; referencebeing hadto the accompanying draw- Fig. 5, a cross-section of a modification of ings, and to the letters of reference marked Fig. 1.

thereon. A is a piece of felting, papier-mach, vul- 60 This invention relates particularly to the canized fiber, or other tough flexible insulatbetter insulation of lines of rails when the ing material, placed under and around the rails of each line of rails are electrically united rail'B, and extending up the web a to about and form conductors for conveying an electric the head of therail, forming an insulating-shoe.

current for utilization along the line of rails. O is a washer-piece, of metal, which is 6 Where it is attempted to use the rails of a placed between A and the spikes, protecting railroad-track as the conductors for an electri- A from injury by the spikes. In place of the cal current, there is .always more or less surpiece 0, wooden pieces D may be used.

facefconduction, the amount depending large- The foot Z) and web a of the rails are cov- 1y upon the dampness or dryness. of the adjaered with some elastic insulating composition, cent soil, the ties, 8m. leaving only the head of the rail exposed or l The object of this invention is to largely rein condition to form a connection for conducduce or to prevent entirely this surface-contion of current. This composition may be a 2 5 duction, to which end the invention consists rubber paint or a paint having a base of pure in the features more particularly hereinafter linseed-oil, or any oxidizable oil. By these 7 described and claimed. means surface conduction or leakage is almost, Between the rail and the tie is placed a piece if not entirely, obviated, causing increased of felt, papier-mach, or other tough flexible economy in the use of electric motors for trac- 30 insulating material, preferably so treated as tion purposes on railroads.

to make it water-proof, which piece extends What I claim is upward on the web on both sides of the rail to ,1. A railway-rail provided with an insulatthe head, forming an insulatingshoe. Being-covering except upon its head, substantween it and-the spike is placed a piece of tially as set forth. 3 5 metal, of the general configuration of the foot 2. An insulating-cushion for railroad-rails,

of the rail, upon which the head of the spike composed of a flexible waterproof fibrous matakes andbears, so that the insulating mate- .terial, substantially as set forth. rial is protected from abrasion or damage by 8. A line of rails electrically connected to the spike. Instead of this metal piece, amuch form a circuit or part of a circuit, and having 40 heavier piece of wood may be used, forming the foot and web of the rails covered with an a shoe fastened down by the spike, and in turn elastic insulating composition adhering to the securing the rail. surface thereof, substantially as set forth.

It will be observed that the insulating nia- This specification signed and witnessed this terial which is placed under and around the 6th day of August, 1880. rail where it rests on the tie is a tough mate- T 45 rial. Rubber will not answer the purpose; THOS EDISOL' but a flexible water-proof fibrous material is Witnesses:

preferred. The foot and web of the rails are F. L. GRIFFIN, covered with some elastic insulating composi- WVM. GARMAN. 

